2.5 Response and Regulation Flashcards
Sense organ defintion
Groups of receptor cells which detect and respond to stimuli
List stimuli
Light, sound, touch, temperature, chemicals
What does each group of receptor cells respond to
A specific stimulus
components of the nervous sytstem
brain, spinal cord and nerves
components of central nervous system
brain and spinal cord
How the CNS works
Body senses a stimulus
Sense organ sends an electrical impulse along a nerve to the CNS
CNS sends an impulse along a nerve to the appropriate part of the body
This part of the body reacts; this reaction is called a response
Reflex action properties
Fast, involuntary and protective
Stimulus defintion
A change in the environment that can be detected
Receptor defintion
An organ that detects the stimulus
Coordinator definition
Detects the signal from the receptor and sends a signal to the effector
Effector defintion
The part of the body (usually a muscle) that carries out/produces the response
Response defintion
The action carried out
Sensory neurone
from receptor to spinal cord
relay neurone
from sensory neurone to motor neurone
motor neurone
from relay neurone to effector
synapse
the tiny gap the impulse travels across
5 steps of a reflex arc
- The stimulus is received/detected by the receptor
- An impulse is sent along the sensory neurone to the spinal cord
- The impulse moved across a tiny gap (synapse) to the relay neurone
- The relay neurone transmits the signal to the motor neurone via another synapse
- The motor neurone stimulates the effector (muscle) to respond
Function of the retina
Has light sensitive cells that detect light
Optic nerve
Conveys nerve impulses from the retina to the brain
Blind spot
The gap in the retina where the optic nerve is attached to (your brain fills it in)
Sclera function
Tough white protective outer layer